28 Mar 2005 15:53:37
Sharpening Rollerski Ferrules

Hi,

I have a question about sharpening rollerski ferrules. Whenever I try
to use my current poles / ferrules, I have horrible slipping problems.
The concrete is fine acctually, it is very fresh, so I assume it is my
ferrules.

Basically what happens is that I can plant them OK 90% of the time, but
every time the tips get approximentally 2 feet past the tail of my
rollerskis, they slip. I'm assuming this is not normal, since in all of
the rollerski videos I have seen, the poles never slip, the person in
the video just lifts the pole up and brings it back forward.

Currently I have a diamond whetstone which I have tried to use to
sharpen the tips but to no avail. Anyone have any tips? How sharp do
the ferrules need to be? Sharp enough to draw blood? And lastly, should
I invest in a bench grinder and a special wheel to sharpen my pole
tips? Any experiances?

Thanks.



28 Mar 2005 16:37:55
Derick Fay
Re: Sharpening Rollerski Ferrules

In my very limited rollerski experience I have found the technique
described here to be effective:
http://www.nordicskiracer.com/Equipment/SharpenPoles.asp

But I have also found that no matter how much I've sharpened, my poles
slip a bit on concrete. On asphalt they're fine.


goingforspeed@gmail.com wrote:
> Hi,
>
> I have a question about sharpening rollerski ferrules.



28 Mar 2005 16:57:17
Re: Sharpening Rollerski Ferrules

I have a hand-crank grinder that I bought from one of those midwest ski
shops a while back for $50. It works great. Never had much luck with
diamond whetstones - too much work and they wear out.

If you're really anal you'll sharpen before each time you go out. And,
as Derick says, forget about getting good grip on concrete.

bt



28 Mar 2005 17:22:24
Jim Grau
Re: Sharpening Rollerski Ferrules

I've had reasonable luck using a diamond file, but only after I got
smart and made a simple jig to hold the two tips parallel and a few
inches apart. With the jig I can sharpen both tips at the same time
and keep the file in a fixed plane. This is basically the same way
ice-skate blades are sharpened.

Jim



28 Mar 2005 20:16:37
Marsh Jones
Re: Sharpening Rollerski Ferrules

goingforspeed@gmail.com wrote:
> Hi,
>
> I have a question about sharpening rollerski ferrules. Whenever I try
> to use my current poles / ferrules, I have horrible slipping problems.
> The concrete is fine acctually, it is very fresh, so I assume it is my
> ferrules.
I've got a mile section of uphill concrete on my 'home loop' that I just
use for a legs-only workout. It's very difficult to get a reliable pole
plant on concrete, plus it dulls the tips very quickly.

As for grinding, you can use a bench grinder with a 'green stone' wheel.
Sorry, don't recall the compound, but it needs to be hard enough to
handle carbide. Keep the tip cooled off by dipping it in a cup of water
OFTEN while you grind, and wear goggles. Make sure to keep them
ground to the original profile - don't try to sharpen the 'forward edge'.

Also, I've found that in general, I get a little more reliable pole
plant if I bring my poles pretty vertical before I plant them. Maybe
digs in a little better.

Good luck and wear that helmet!

Marsh Jones
>
> Basically what happens is that I can plant them OK 90% of the time, but
> every time the tips get approximentally 2 feet past the tail of my
> rollerskis, they slip. I'm assuming this is not normal, since in all of
> the rollerski videos I have seen, the poles never slip, the person in
> the video just lifts the pole up and brings it back forward.
>
> Currently I have a diamond whetstone which I have tried to use to
> sharpen the tips but to no avail. Anyone have any tips? How sharp do
> the ferrules need to be? Sharp enough to draw blood? And lastly, should
> I invest in a bench grinder and a special wheel to sharpen my pole
> tips? Any experiances?
>
> Thanks.
>


29 Mar 2005 02:20:48
Gary Jacobson
Re: Sharpening Rollerski Ferrules

Get a green (soft) grinding stone from any good tool seller. And....

Instant replay from the past:

Newsgroups: rec.skiing.nordic
From: "Gary Jacobson" <skateklis...@hotmail.com > - Find messages by this
author
Date: 2000/07/28
Subject: Reason why soft grinding wheels sharpen hard ski pole tips
Reply to Author | Forward | Print | Individual Message | Show original |
Report Abuse

Cross country skiing relates to and is a product of so many aspects of the
natural world explained by scientific disciplines. I guess this post deals
with friction in the mechanical engineering realm. Don't really know that,
but anyways I have always been baffled by why a "soft" rotating grinding
stone works to sharpen a hard carbide ski pole tip,
especially because we know that a hard diamond hand stone works well. (This
may be somewhat akin to the often querried: Why isn't a hard glide wax
always faster than a soft glide wax?)


I looked the answer up, and what follows is mostly paraphrase from a text
book. I am no expert in this matter in any way, but that doesn't mean I
can't post a message on the internet as though I am. :)


First off grind stones generally are rotating between 5500 and 6000 feet per
second. The hardness of the stone is called "grade", and refers to the
tenacity with which the bond holds cutting particles or abrasive grains, and
not to the hardness of the abrasive. (uh ha!- the answer!)


The choice of grade and grain depends on the hardness and amount of surface
area of the material in contact with the wheel. In theory the choice is the
proper grade when the bond is just hard enough to hold the abrasive until it
becomes too dull to cut effectively. Then, because of increased friction the
dulled grain is torn off the wheel and new abrasive points are exposed.
Therefore the wheel sharpens itself.


If a hard wheel is used to grind an hard ski tip then the grains are dulled
faster than they are torn off. This causes glazing of the wheel, and would

require excessive pressure to be used to cut. Also it would heat things up
too much and the tip might melt out of the ferrule.)


Ideally light pressure is used when grinding, if the goal is to remove a lot
of material, and the "polish" of the surface is not
important.


Generally the more surface are contact with the wheel the softer
the grade should be.


The grade or coarseness of the the wheel depends upon the hardness of the
material, and how well the finished job needs to look. Coarse grades are
best for most work, and it would seem that the best grinding wheels for
carbide tips are soft coarse ones.

Gary Jacobson
Rosendale, NY




28 Mar 2005 21:33:56
Gene Goldenfeld
Re: Sharpening Rollerski Ferrules

I've found new, fine asphalt isn't the easiest to get a good plant in.
It seems to take awhile for the grain to separate enough. However, do
make sure you are keeping pressure on the pole all the way through. A
diamond whetstone should do the trick well enough, but manual grinders
sold by some shops are worth it, if you don't have access to one. Since
the grinder's sharpening doesn't have to be redone that often, maybe you
can recoup the cost by charging friends for grinds. ;)

Gene

goingforspeed@gmail.com wrote:
>
> Hi,
>
> I have a question about sharpening rollerski ferrules. Whenever I try
> to use my current poles / ferrules, I have horrible slipping problems.
> The concrete is fine acctually, it is very fresh, so I assume it is my
> ferrules.
>
> Basically what happens is that I can plant them OK 90% of the time, but
> every time the tips get approximentally 2 feet past the tail of my
> rollerskis, they slip. I'm assuming this is not normal, since in all of
> the rollerski videos I have seen, the poles never slip, the person in
> the video just lifts the pole up and brings it back forward.
>
> Currently I have a diamond whetstone which I have tried to use to
> sharpen the tips but to no avail. Anyone have any tips? How sharp do
> the ferrules need to be? Sharp enough to draw blood? And lastly, should
> I invest in a bench grinder and a special wheel to sharpen my pole
> tips? Any experiances?
>
> Thanks.


28 Mar 2005 21:36:56
Gene Goldenfeld
Re: Sharpening Rollerski Ferrules

Missed that concrete. Your experience is normal. Find asphalt and
minimize poling on concrete to save your tips.

gene

Gene Goldenfeld wrote:
>
> I've found new, fine asphalt isn't the easiest to get a good plant in.
> It seems to take awhile for the grain to separate enough. However, do
> make sure you are keeping pressure on the pole all the way through. A
> diamond whetstone should do the trick well enough, but manual grinders
> sold by some shops are worth it, if you don't have access to one. Since
> the grinder's sharpening doesn't have to be redone that often, maybe you
> can recoup the cost by charging friends for grinds. ;)
>
> Gene


29 Mar 2005 03:42:35
Gary Jacobson
Re: Sharpening Rollerski Ferrules


I've encountered asphalt with a quartz or quartzite aggregate. That's do a
number on tips and technique too.

Gary Jacobson
Rosendale, NY where we most certainly skied for the last time yesterday on
one foot of snow. Warms temps and liquid deluge now and for the coming
days..


"Gene Goldenfeld" <genegold@highstream.net > wrote in message
news:4248CD58.69CE13D6@highstream.net...
> Missed that concrete. Your experience is normal. Find asphalt and
> minimize poling on concrete to save your tips.
>
> gene
>
> Gene Goldenfeld wrote:
> >
> > I've found new, fine asphalt isn't the easiest to get a good plant in.
> > It seems to take awhile for the grain to separate enough. However, do
> > make sure you are keeping pressure on the pole all the way through. A
> > diamond whetstone should do the trick well enough, but manual grinders
> > sold by some shops are worth it, if you don't have access to one. Since
> > the grinder's sharpening doesn't have to be redone that often, maybe you
> > can recoup the cost by charging friends for grinds. ;)
> >
> > Gene




29 Mar 2005 10:35:14
Jim Grau
Re: Sharpening Rollerski Ferrules

There's a really delightful rail trail going south from Adams, MA (past
Berkshire Outfitters) that I've had lots of fun inline skating on;
HOWEVER, when I tried roller skiing on it once I couldn't get a pole
plant to stick no matter how hard I tried. I don't know what that
stuff was made out of, but it LOOKED like asphalt -- it was rather
smooth, but not concrete smooth.

The folks who pave rail trails should really check with RSN first :)

-Jim